Curvature Diagram

There are two curvature diagram tools in the software; Horizontal Curvature Diagram and Vertical Curvature Diagram. These works similarly and can be accessed from the following location:

Ribbon: OpenRail Modeling > Rail > Regression > Curvature Diagram.

Commands display a diagram representing curvature along the path of regression points. The horizontal axis represents stationing along the alignment. The vertical axis indicates 1/radius.

The purpose of the curvature diagram is to help you distinguish the arcs, spirals, and tangent sections in an alignment, based on the regression data. This command operates on raw regression data; you do not need to perform any regression analysis before running this command.

The curvature at any given regression point is determined by fitting an arc through that point and the previous and next regression points (a three-point arc). The radius of the computed arc is then associated with the given regression point.

Selection of the points are done with a selection box, which allows excluding any unwanted points. Any point that are in the selection range but not included in the selection box, will have its status set to “Ignore Point” and will be removed from the diagram. To include these points back into the diagram, please use relevant horizontal or vertical point table (see Horizontal Regression Point Table).

As elements are created and added to the regression complex, the point representations in the curvature diagram are updated to reflect the new element created at the point location (different color for curves and lines).